BRL-CAD
pipe_mirror.c
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1 /* P I P E _ M I R R O R . C
2  * BRL-CAD
3  *
4  * Copyright (c) 2009-2014 United States Government as represented by
5  * the U.S. Army Research Laboratory.
6  *
7  * This library is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public License
9  * version 2.1 as published by the Free Software Foundation.
10  *
11  * This library is distributed in the hope that it will be useful, but
12  * WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this file; see the file named COPYING for more
18  * information.
19  */
20 /** @file primitives/pipe/pipe_mirror.c
21  *
22  * mirror support
23  *
24  */
25 
26 #include "common.h"
27 
28 #include "raytrace.h"
29 #include "rtgeom.h"
30 #include "wdb.h"
31 
32 
33 /**
34  * Given a pointer to an internal GED database object, mirror the
35  * object's values about the given transformation matrix.
36  */
37 int
38 rt_pipe_mirror(struct rt_db_internal *ip, register const plane_t plane)
39 {
40  struct rt_pipe_internal *pipep;
41 
42  mat_t mirmat;
43  mat_t rmat;
44  mat_t temp;
45  vect_t nvec;
46  vect_t xvec;
47  vect_t mirror_dir;
48  point_t mirror_pt;
49  fastf_t ang;
50 
51  struct wdb_pipept *ps;
52 
53  static point_t origin = {0.0, 0.0, 0.0};
54 
56 
57  pipep = (struct rt_pipe_internal *)ip->idb_ptr;
58  RT_PIPE_CK_MAGIC(pipep);
59 
60  MAT_IDN(mirmat);
61 
62  VMOVE(mirror_dir, plane);
63  VSCALE(mirror_pt, plane, plane[W]);
64 
65  /* Build mirror transform matrix, for those who need it. */
66  /* First, perform a mirror down the X axis */
67  mirmat[0] = -1.0;
68 
69  /* Create the rotation matrix */
70  VSET(xvec, 1, 0, 0);
71  VCROSS(nvec, xvec, mirror_dir);
72  VUNITIZE(nvec);
73  ang = -acos(VDOT(xvec, mirror_dir));
74  bn_mat_arb_rot(rmat, origin, nvec, ang*2.0);
75 
76  /* Add the rotation to mirmat */
77  MAT_COPY(temp, mirmat);
78  bn_mat_mul(mirmat, temp, rmat);
79 
80  /* Add the translation to mirmat */
81  mirmat[3 + X*4] += mirror_pt[X] * mirror_dir[X];
82  mirmat[3 + Y*4] += mirror_pt[Y] * mirror_dir[Y];
83  mirmat[3 + Z*4] += mirror_pt[Z] * mirror_dir[Z];
84 
85  for (BU_LIST_FOR (ps, wdb_pipept, &pipep->pipe_segs_head)) {
86  point_t pt;
87 
88  VMOVE(pt, ps->pp_coord);
89  MAT4X3PNT(ps->pp_coord, mirmat, pt);
90  }
91 
92  return 0;
93 }
94 
95 
96 /*
97  * Local Variables:
98  * tab-width: 8
99  * mode: C
100  * indent-tabs-mode: t
101  * c-file-style: "stroustrup"
102  * End:
103  * ex: shiftwidth=4 tabstop=8
104  */
#define BU_LIST_FOR(p, structure, hp)
Definition: list.h:365
#define VSET(a, b, c, d)
Definition: color.c:53
Header file for the BRL-CAD common definitions.
Definition: color.c:49
#define RT_CK_DB_INTERNAL(_p)
Definition: raytrace.h:207
void bn_mat_mul(mat_t o, const mat_t a, const mat_t b)
int rt_pipe_mirror(struct rt_db_internal *ip, register const plane_t plane)
Definition: pipe_mirror.c:38
void * idb_ptr
Definition: raytrace.h:195
Definition: color.c:51
double fastf_t
Definition: defines.h:300
void bn_mat_arb_rot(mat_t m, const point_t pt, const vect_t dir, const fastf_t ang)
Definition: mat.c:987
Definition: color.c:50